Copeptin as a part of the dual biomarker strategy for early diagnosis of non ST segment elevation myocardial infarction WILCOP study

Abstract

Background: The major shortcoming of cardiac troponin (cTn) is its incapability to generally detect an acute coronary syndrome (ACS) in the hours after symptom onset, due to the delayed increase of its circulating levels after the actual ACS occurrence (so-called silent Troponin time). We have investigated the effect of combined measurement of copeptin and high sensitivity cardiac troponin I (hs-cTnI) levels for identification of patients with NSTEMI. Methods: This is an ongoing prospective single-centre study of consecutive patients admitted to the emergency department (ED) of our hospital with chest pain suggestive of ACS. Present analysis reports data of the first 577 consecutive patients. All patients had baseline copeptin and hs-cTnI measurements. Results: In total, 82/577 (14.2%) patients had angiography-confirmed diagnosis of ACS, with 44/82 (53.6%) pats. with diagnosis of NSTEMI. The diagnostic accuracy of cTnI for diagnosis of NSTEMI for the entire study population was convincingly higher (AUC 0.916; p<0.001) than that of Copeptin (AUC 0.610). Utilization of the dual biomarker strategy in overall study population by combining both biomarkers increased considerably the diagnostic accuracy for NSTEMI with AUC 0.926 (p<0.001) and NPV of 98.4% (96.32-99.34; 95% CI). The group of patient that presented to ED inside the 6 hours after onset of symptoms (so-called early presenters) comprised 45.4% of the total study population (262/577 pats.). In this group of patients diagnostic accuracy of cTnI alone for NSTEMI was lower (AUC 0.870; p<0.001) than in the overall study population (AUC 0.916). The additional use of copeptin levels in this early presenters group reinforced the diagnostic precision for identifying the patients with NSTEMI, quantified with AUC of 0.920 (p<0.001). Conclusion: Measurement of hs-cTnI at admission to ED had fairly good diagnostic accuracy for identification of patients with NSTEMI. However, among patients with initially normal hs-cTnI levels, presenting after the onset of symptoms (inside 6h after symptom onset), there exists promising diagnostic relevance of simultaneous measurement of copeptin levels (dual marker strategy) for a prompt and reliable diagnosis of NSTEMI.